What is the risk of developing cancer due to genetic inheritance?

We discuss the influence of inherited genes on Cancer susceptibility.

"Cancer" is the name given to a number of related diseases in which an uncontrolled process of cell division is observed in some part of the body.

Of course, this clinical definition does not do justice to the pain and suffering that these pathologies generate in modern society.

Cancer goes far beyond a terminological conglomerate, as we all know someone who has suffered from it, and certainly, we present a non-negligible risk of facing it at some point in our lives. Unfortunately, this is one of the leading causes of death in the world, with cancers of the respiratory tract ranking eighth in terms of global deaths, while cancer in general ranks second in high-income countries, just behind cardiovascular disease.

As grim and unpleasant as this topic may be, confronting the enemy and knowing it is the first step to being able to end it. Therefore, this time we explore the risk of developing cancer due to genetic inheritanceamong other issues related to this group of diseases that are so difficult to deal with. Let's get to it.

Risk of developing cancer by genetic inheritance: a family matter?

It is difficult to understand the magnitude of cancer in society if we are not exposed to certain facts and figures. The National Cancer Institute (NIH) provides the following information:

• Each year 439 cases of cancer are diagnosed per 100,000 men and women. The mortality rate for this group of pathologies is 163 deaths per 100,000 inhabitants per year.
• The most common cancers are breast, lung, prostate and colon cancer, among others.
• In the United States alone, it is estimated that almost 2 million new cases are diagnosed each year.

Things get worse if we look at these figures as cumulative and not isolated. Yes, nearly 500 cases of cancer are diagnosed every year for every 100,000 people, it doesn't sound like much. The key is that the probabilities are annualthat is, cumulative over an individual's lifetime.

Thus, it is estimated that an American man has an 11% chance of developing colon cancer in his lifetime (absolute risk), not counting the odds of the other variants. The most frightening figure of all is the following: almost 40% of the human population will be diagnosed with cancer at some point in their lives.

These data must be contextualized, as it is certainly not the same for a neoplasm to be detected in a 90-year-old as it is for a malignant tumor to be detected in a 30-year-old. Numerical figures should be dissected according to age groups, risk factors and other considerations.. In addition, in 2016 there were more than 15 million cancer survivors in the united states, so this diagnosis correlates less and less directly with death. In short: there is no need to panic.

Despite this call for calm and necessary appreciation for the fight against hypochondrism, we cannot deny that these data show that cancer is here to stay in our society. For this reason, exploring factors such as the risk of developing cancer due to genetic inheritance is essential.. We show you what is known so far.

A question of genes

First of all, it is necessary to differentiate a hereditary syndrome of familial cancer from an environmental issue.. If several people in a family smoke, it is no surprise that more than one of the members can develop lung cancer, since up to 90% of deaths from these neoplasms are related to tobacco consumption. The same occurs with obesity, for example, which can promote the appearance of these types of cancer.

If a family is in an area full of pollutants, works together in an unhealthy environment, has inadequate general habits and many other factors, it is natural to think that its members will have more chances of developing cancer. This does not necessarily correspond to a genetic predisposition, but rather an environmental or behavioral one.

Having clarified this issue, it is necessary to elucidate that hereditary cancer syndromes do exist. It is estimated that 5-10% of cancerous processes are associated with heritable genetic factors.Researchers have associated mutations in more than 50 specific genes that predispose carriers to this group of diseases.

Once the term "mutation" has been introduced, it is essential that we frame it within the etiology of cancer. As mentioned above, the malignant tumor process is due to a cell mutation, whereby these cells divide abnormally fast and do not comply with the typical cell death and proliferation times. This gives rise to the dreaded tumor, an abnormal mass of tissue that does not respond to any biological function. Thus, the genetic mutations that promote this situation can be inherited or acquired:

Mutations of an inherited nature are present in the egg or sperm that form the child.. Since all the cells of the fetus come from a single primordial cell, we can affirm that this type of mutation is found in every cell of the individual (including eggs and sperm), so it can be transmitted to the following generations.

On the other hand, we have somatic or acquired mutations, which do not originate from one of the parents.which do not come from one of the parents but occur during the lifetime of the individual. In this case, the mutation originates in a cell of a specific tissue, and the entire descendant cell lineage will present it, but the body cells already formed or dividing independently of the cancerous cell will not have it. Most cancers are caused by this type of mutation.

A specific case: breast cancer

In the case of the risk of developing cancer due to genetic inheritance, we can say that many familial cancer syndromes are caused by inherited mutations in tumor suppressor genes. These genes are of essential importance, as they control cell growth, correct replication errors and indicate when cells should die..

We may err on the side of reductionism, but let's explain this conglomerate in the friendliest possible way: we have two copies of each gene (one from the father and one from the mother), so inheriting an abnormal gene should not be a problem as long as the other is functional.

Things get complicated when the second copy of the inherited gene stops working (perhaps because of an acquired mutation, or because the other parent also has the defective gene), since in this case, as the two copies are "wrong", it is not a problem, in this case, as both copies are "bad", the tumor suppressor gene may lose its functionality.. Naturally, this translates into a greater chance of developing cancer.

An exemplary case of this is breast cancer, since it has been reliably demonstrated that 5% of cases are related to genes of autosomal dominant inheritance. For example, mutations in certain genes such as BRCA1 and BRCA2 are clearly correlated with breast and ovarian cancer processes. Since these genes are involved in the process of tumor suppression and gene repair, it is not surprising that their inactivation or defective regulation increases the likelihood of developing certain types of malignant tumors.

Summary

Is there a risk of developing cancer due to genetic inheritance? Yes, because as we have said, 5 to 10% of cancers are related to hereditary factors. Should I worry about getting cancer if a close relative has suffered from it? Unless your doctor indicates you to undergo tests associated with the genetic field, no. You should not.

You only need to look at these data to dismiss any trace of hypochondrism: 5% of cancers are caused by genetic predisposition, 10% by occupational conditions, and the remaining 80-90% by lifestyle habits. Although this is a statement that requires multiple meanings, we prefer this to be the general message.

In most cases cancer does not appear magically, as factors such as smoking, alcoholism or obesity are clearly correlated with this group of diseases. factors such as smoking, alcoholism and obesity are clearly correlated with this group of diseases.. Therefore, in our lifestyle lies the key to survival, beyond any genetic conditioning.

Bibliographic references:

• Caldés, T. (2006). Hereditary cancer: genetic foundations. Psycho-oncology, 2(2), 183-96.
• Genetics of cancer, Clinic Barcelona. Retrieved September 30 from https://www.clinicbarcelona.org/asistencia/enfermedades/cancer/genetica-del-cancer#:~:text=El%20c%C3%A1ncer%20es%20una%20enfermedad,el%20que%20est%20C3%A1n%20los%20genes.
• Cancer%20genetics,%National%20cancer%20institute%20(NIH). Retrieved September 30 from https://www.cancer.gov/espanol/cancer/causas-prevencion/genetica#2.
• Cancer risk: what the numbers mean, Mayoclinic.org. Retrieved September 30 from https://www.mayoclinic.org/es-es/diseases-conditions/cancer/in-depth/cancer/art-20044092#:~:text=The%20absolute%20risk%20is%20of,approximately%20one%2011%20per%20per%20percent.
• Cancer syndromes in families, American Cancer Society. Retrieved September 30 from https://www.cancer.org/es/cancer/causas-del-cancer/genetica/sindromes-de-cancer-familiar.html.